(* only the open bracket is added; the closed bracket must be in b *)
Mtable(attr@standard_tbl_attr,
[Mtr([],[Mtd([],Mrow([],[Mtext([],"(");a]))]);
(* only the open bracket is added; the closed bracket must be in b *)
Mtable(attr@standard_tbl_attr,
[Mtr([],[Mtd([],Mrow([],[Mtext([],"(");a]))]);